矩形断面恒定非均匀流水面线计算解析

Analytical Solution of Surface Line of Constant Non-uniform Flow in Rectangular Channel

针对无压泄洪隧洞在运行过程中水流流态较复杂的问题,依托青山水库泄洪隧洞改造工程,对无压泄洪隧洞中矩形断面恒定渐变流水面线计算解析进行了数学推导,给出了流程S与始、末端水深之间的解析解;比规范推荐分段试算法更简单便捷,进而通过青山水库泄洪隧洞改造工程1∶30水工模型试验成果对比分析,认为推求的沿程水面线计算解析解合理可靠,为确保泄洪渠及下游河道行洪安全提供了依据,可供类似工程参考应用。

Aiming at the complicated water flow during the operation of pressureless flood-discharge tunnel,based on the flood-discharge tunnel reconstruction of Qingshan Reservoir,a mathematical derivation for the calculation and analysis of water surface line of constant gradient flow with rectangular section in the unpressurized flood-discharge tunnel is made,and the analytical solution between flow S and water depth at the beginning and end is given,which is more simple and convenient than the standard recommended piecewise trial algorithm.Finally,through the comparative analysis of 1∶30 hydraulic model test results of the flood-discharge tunnel reconstruction project of Qingshan Reservoir,it is believed that the calculation and analytical solution of water surface line along the route is reasonable and reliable,providing a basis for the safety of flood-discharge channels and downstream river,which can be used as a reference for similar projects.